Preparation,Crystal Structure and Density Functional Theory Calculations of the Ion-pair Compound [Cl2Bz（3-MeQl）]（TCNQ）

A novel compound [Cl2Bz(3-MeQl) ](TCNQ) ([Cl2Bz(3-MeQl) ]+ = 1-(3,4-dichlo-robenzyl) 3-methlquinoline cation,TCNQ-= 7,7,8,8-tetracyanoquinodimethanide anion) has been synthesized by the reaction of [Cl2Bz(3-MeQl) ]Br and LiTCNQ,and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic,space group P21/c. The structure analysis shows that the anions are stacked into a column with isolated π-dimers,and there is one type of TCNQ entries(TCNQ) ,in agreement with the IR spectra analysis and density functional theory calculations of the compound. The most prominent structural features are the completely segregated stacking columns of the TCNQ- anions and [Cl2Bz(3-MeQl)]+ cations.     

An Alcohol-templated Borate Based on [B14O20（OH）6]4- Polyborate Anions

A new borate [H2EG][B7O10（OH）3] （1） based on [B14O20（OH）6]4- polyborate anions has been solvothermally synthesized in the presence of H2EG as a template （EG = ethylene glycol）. The structure was determined by single-crystal X-ray diffraction and further characterized by FFIR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the triclinic system, space group Pi, with a = 8.5095（4）, b = 8.8694（4）, c = 10.0756（4） A, a = 95.094（2）, β = 96.936（2）, γ = 116.844（2）°, V = 664.66（5） A3. The structure of 1 consists of [B14O20（OH）6]4- moiety, which could be regarded as the largest isolated polyborate anion so far. The anions are interlinked via hydrogen bonding to form a 3D supramolecular network, whereas the diprotonated [H2EG]2＋ are filled in the free space of inorganic borate network and interact with the inorganic framework by extensive hydrogen bonds. It is noteworthy that the EG acts not only as a solvent, but also as a template.     

Synthesis and Crystal Structure of a Novel Ion-pair Compound Consisting of 1,3-Bis（4-cynobenzyl） Imidazole Cation and 7,7,8,8-Tetracyanoquinodimethanide Anion

A novel compound [(CNBz)2Im]2(TCNQ)3(CH3CN)((CNBz)2Im = 1,3-bis(4-cyano-benzyl) imidazole cation,TCNQ-1 = 7,7,8,8-tetracyanoquinodimethanide anion) was synthesized by the reaction of [(CNBz)2Im]Br and LiTCNQ in water and its structure was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/c with a = 10.1823(17),b = 20.292(3),c = 16.952(3) ,β = 104.73(0)°,V = 3387.6(10)3,Z = 4,C39H24N11,Mr = 646.69,Dc = 1.268 g/cm3,μ = 0.080 mm-1 and F(000) = 1340.The structure was solved by direct methods and refined to R = 0.0596 and wR = 0.0911 for 2690 observed reflections(Ⅰ 2σ(Ⅰ)).The most prominent structural feature is that there are two types of TCNQ entries(TCNQ-1 and TCNQ0) in agreement with the IR spectra analysis of the compound.     

Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Supramolecular Compound {[2-（2-Pyridyl）benzimidazoleH2]2＋ ·[SbCls]2-}2

A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetfic analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 16.0397（13）, b = 14.3189（12）, c = 15.6370（13） A, β = 105.8980（10）°, V = 3454.0（5） A3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3,/z = 2.366 mm-1, S = 1.010, F（000） = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, [SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3＋ ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb...Cl. Moreover, the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-（2-pyridyl）benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.     

Structural Evidence of Anion＇s Effect on the Ion Packing of [Ni2（teta）3]^4＋ in the View of H-bonding Interaction

Two dinuclear nickel（Ⅱ） complexes [Ni2（teta）3]Cl4＇2H2O1 and [Ni2（teta）3]（NO3）4 2 （teta = triethylenetetramine） were synthesized by a solvothermal method and structurally characterized. Complex 1： orthorhombic, Pbca, a = 13.791（3）, b = 13.078（3）, c = 18.323（4） ,A, V = 3304.8（12） A3, Z = 4, Mr= 733.98, Dc = 1.475 g/cm^3,μ = 1.500 mm^-1, F（000） = 1560, R = 0.0585 （I 〉 20（/）） and wR = 0.1243. Complex 2： orthorhombic, P212121, a = 7.8279（14）, b = 14.209（3）, c = 31.163（6）A, V = 3466.2（11）A3, Z = 4, Mr= 804.19, Dc = 1.541 g/cm^3,μ = 1.164 mm^-1 F（000） = 1704, R = 0.0401 and wR = 0.0840 for 5950 observed reflections （I 〉 2σ（I））. Two Ni^2＋ ions are connected by one linear bridging teta ligand, forming a dinuclear [Ni2（teta）3]^4＋ cation. Each Ni^2＋ ion in 1 and 2 takes a distorted octahedral geometry with six coordinated N atoms from two teta ligands. The effect of different anions on the arrangement of [Ni2（teta）3]^4＋ cations has been discussed in view of H-bonding interactions. Thermal stability of 1 and 2 was also investigated.     

Syntheses,Structures and Band Gaps of KLnSiS4 （Ln = Sm,Yb）

Two new quaternary sulfides, KSmSiS4 （1） and KYbSiS4 （2）, have been synthesized by high-temperature solid-state reaction. Single,crystal X-ray diffraction analyses indicate that both compounds crystallize in the space group P21/m, and the crystal data are as follows： a = 6.426（11）, b = 6.582（11）, c = 8.602（15）A, β= 107.90（13）°, Z = 2, V= 346.2（10） A^3, Dc = 3.317 g/cm^3, F（000） = 318,μ（MoKα） = 10.334 mm^-1, the final R = 0.0559 and wR = 0.1370 for 1; and α= 6.3244（10）, b = 6.5552（10）, c = 8.5701（15）A, β= 108.001（13）°, Z = 2, V = 337.91（9） A^3, De= 3.621 g/cm^3, F（000） = 334, μ（MoKα） = 15.737 mm^-1, the final R = 0.0422 and wR = 0.0960 for 2. The KLnSiS4 （Ln = Sm, Yb） structure consists of corrugated ∞^2 [LnSiS4]^- layers which are formed by edge-sharing LnS8 bicapped trigonal prisms and SiS4 tetrahedra. The K^＋ cations are located in the cavities defined by S2 anions between the ∞^2[LnSiS4]^- layers. Band-gap analyses show that compounds 1 and 2 are semiconductors with optical band-gaps of 2.40 and 2.34 eV, respectively.     

Hydrothermal Synthesis and Crystal Structure of a New Three-dimensional Co（II） Coordination Polymer Based on 2,3-Thiophenedicarboxylic Acid

A new Co（ll） polymer [Co（tdc）（l,4-bimb）]n 1 （H2tdc = thiophene-2,3-dicarboxy- lic acid, 1,4-bimb -- 1,4-bis（imidazol-1 ＇-yl）butane） was synthesized under hydrothermal conditions The compound crystallizes in the monoclinic system, space group C2/c with a = 15.643（9）, b = 8.839（5）, c=12.952（7） A, β = 105.964（6）°, V= 1721.8（16） A3, Z = 4, Mr = 419.32, Dc= 1.618 Mg/m3,μ = 1.149 mm-1, F（000） = 860, the final R = 0.0243 and wR =0.0613 for 1460 observed reflections with I 〉 2σ（I）. The compound presents a three-dimensional （3D） network extended by both tdc2- anions and 1,4-bimb ligands in which the tdc2- anions employ a chelating coordination mode. From the topology point of view, the structure could be described as a 3D 4-connected 65.8 CdSO4-type net. Infrared spectroscopy, elemental analyses, thermogravimetric analysis and powder X-ray diffraction properties of 1 are also investigated.     

Synthesis and Crystal Structure of [K（2,2,2-crypt）]2HP11

[K（2,2,2-crypt]2HP11 has been prepared from the reaction of K3P11 with the mixed ethylenediamine/2,2,2-crypt solution. The crystal structure was determined by singlecrystal X-ray diffraction. The crystal is of tdgonal system, space group P^-3c1 with a = 12.068（2）, b = 12.068（2）, c = 22.319（6）A, V = 2815.0（10）A^3, Dc = 1.384 g/cm^3, C36h73K2N4O12P11, Mr = 1172.85, F（000） = 1232,μ = 0.536 mm^-1, Z= 2, R = 0.0678 and wR = 0.2211 for 1763 observed reflections （I 〉 2σ（I））. In this compound, the P11 cluster has ideal 32-D3 symmetry, and the three-fold axis, corresponds to the crystallographic c axis. The （HP11）^2- anions are stable due to the completely sequestered alkali metal cations through only ion-ion interactions.     

Synthesis and Crystal Structure of a Novel Tetranuclear Zinc（Ⅱ） Coordination Polymer [Zn4（o-bda）4（p-pbim）4]n

A novel tetranuclear zinc（H） coordination polymer [Zn4（o-bda）a（p-pbim）4]n 1 （p-pbim = 4-pyridylbenzimidazole, o-bda2 = o-phenylenediacetic acid dianion） has been synthesized by a hydrothermal method and characterized by elemental analysis, IR and X-ray singlecrystal diffraction. The title complex crystallizes in monoclinic, space group of P21/n with α = 14.231（1）, b = 16.257（1）, c = 16.794（1） ]k, β = 100.26（1）°, V = 3823.1（2）A3, Z = 8, Dc = 1.573 g/cm^3,β = 1.321 mm^-1, F（000） = 1856, R = 0.0420 and wR = 0.111. The Zn（1） atom assumes a distorted trigonal bipyramidal geometry, involving three carboxyl O atoms from two different o-bda ligands and two N atoms from two p-pbim ligands. The Zn（2） atom is coordinated by two oxygens from two distinct bda2- anions and two nitrogen atoms from two p-pbim ligands to form a distorted tetrahedral geometry. The Zn（Ⅱ） atoms are alternately interlinked by o-bda ligands in bis-monodentate or chelating-bidentate and monodentate modes into one-dimensional undulate chains along axis c with the adjacent Zn…Zn distances of 8.32 and 8.47 A. Such neighboring chains are further extended into a 1D bi-chain structure with two different subrings A and B, which are 32- and 14-membered rings through interchain p-pbim ligands. There exists a 2D supramolecular network linked by intermolecular hydrogen-bonding interactions between the uncoordinated carboxylate 0（4） atom or coordinated carboxylate 0（7） atom and the uncoordinated imidazolyl N（2） and N（5） atoms with the O...N distances to be 2.695 and 2.807A.     

离子对化合物[(IBz)_2Im](TCNQ)的合成与结构表征(英文)

A novel compound [(IBz)2Im](TCNQ) [(IBz)2Im=1,3-bis(4-iodobenzyl) imidazole cation, TCNQ-=7,7,8,8-tetracyanoquinodimethanide anion] was synthesized by the reaction of [(IBz)2Im]Br and LiTCNQ in CH3OH and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a=1.147 35(18) nm, b=2.028 1(3) nm, c=1.264 1(2) nm, β=104.73(0)°, V=2.666(65) nm3, Z=4, C29H19I2N6, Mr= 705.30, Dc=1.757 g·cm-3, R1=0.053 2 and wR2=0.111 2. The structure analysis shows that the anions are stacked into column with isolated π-dimers, and there is one type of TCNQ entries (TCNQ-), in agreement with the IR spectra analysis of the compound. The most prominent structural features are the completely segregated stacking columns of the TCNQ-anions and [(IBz)2Im]+ cations. CCDC: 759523.     

Supramolecular architecture and magnetic properties of copper(II) and nickel(II) porphyrinogen-TCNQ electron-transfer salts

The compounds [Cu(Tz)-(MeOH)2](TCNQ)2 (1), [Ni(Tz)-(MeOH)2](TCNQ)2 (2), [Cu(Tz)2]-(TCNQ)7 (3) and [Ni(Tz)2](TCNQ)7 (4) (Tz = 2,7,12,17-tetramethyl-1,6,11,16-tetraazaporphyrinogen) were obtained by metathesis reaction of [M(Tz)](ClO4)2 with LiTCNQ and Et3NH(TCNQ)2, respectively. They were characterized by a combination of spectroscopic and physical methods. Compound 1 crystallizes in the monoclinic space group P2(1)/n with a = 8.310(2), b = 25.180(4), c = 20.727(4) A, beta = 93.58(2) degrees; Z = 4. Compound 3 crystallizes in the triclinic space group P1 with a = 11.244(1), b = 16.700(1), c = 17.321(1) A, a = 113.47(1), beta = 108.52(1), gamma = 96.12(1) degrees; Z = 2. The asymmetric unit of the compound 1 is formed by cationic [Cu(Tz)(MeOH)2]2+ and by two crystallographically non equivalent TCNQ.- anions; these anions form dimeric units by overlap of the pi clouds. The dimers form hydrogen bonds with the metal-lomacrocyclic cation through the methanol ligands. According to this structure the compound is paramagnetic and behaves as an insulator in the temperature range studied. The paramagnetism arises only from the metal-complex moieties. Compound 3 shows an unprecedented structure due to the steric requirements of the macrocycle that favors the stacking of the TCNQ groups. The structure consists of infinite stacks of TCNQ units separated by the metal-macrocyclic units; there are seven TCNQ molecules per formula unit, one of which is formally mono-anionic, while the other six bear one half of an electron per molecule. The copper is six-coordinate in a very distorted octahedral environment. The Tz ligand is located in the equatorial plane and the apical nitrogens of the nitrile groups of two TCNQ molecules complete the coordination around the copper. The compound is a semiconductor and its magnetic behavior can be explained by the sum of the Curie contribution of the metal complex and the contribution arising from the magnetic-exchange interactions of the spins located on the TCNQ units. The latter is found to be typical of one-dimensional antiferromagnetic distorted chains of S = 1/2 spins and can be fitted according to a one-dimensional Heisenberg antiferromagnetic model.     

Preparation and characterization of [[M(dmb)2]TCNQ.xTCNQo]n polymers (M=Cu,Ag; dmb = 1,8-diisocyano-p-menthane; x = 0, 0.5, 1.0, 1.5; TCNQ = 7,7,8,8-tetracyano-p-quinodimethane) and design of new semi- and photoconducting organometallic materials

New thermoplastic organometallic materials of the type [[M(dmb)2]TCNQ.xTCNQo.y solvent], (M = Cu(I), Ag(I); dmb = 1,8-diisocyano-p-menthane; TCNQ = 7,7,8,8-tetracyano-p-quinodimethane, x = 0, 0.5, 1.0, 1.5; solvent = none, THF or toluene) have been prepared and characterized from X-ray powder diffraction patterns, X-ray crystallography (for some Ag polymers), DSC, and conductivity measurements. While the [[M(dmb)2]TCNQ.xTCNQo]n polymers (M = Cu,Ag; x = 0, 0.5) are insulating, the others (x = 1.0 and 1.5) are semiconducting, and the relative conductivity is found to be a function of the molecular weight and crystallinity. The [[Cu(dmb)2]TCNQ.1.5TCNQ]n material is also photoconducting, while the Ag analogue is not. Photochemical and luminescence quenching experiments in the solid-state established that the Cu+ center and TCNQo act as electron donor and acceptor, respectively, in this photoprocess. Finally photocells of the type glass/SnO2/[Cu(dmb)2]TCNQ.TCNQo]n + 0.5 acceptor/Al (acceptor = TCNQo, C60 and TCNN (13,13,14,14-tetracyano-5,12-naphthacenequinodimethane)) have been designed and characterized. The quantum yields (number of photoproduced electrons/number of photons) are as follows: TCNQ, 1.6 x 10(-4), C60, 5 x 10(-5), TCNN, 3.0 x 10(-4) at lambdaexc = 330 nm. X-ray data for [[Ag(dmb)2]TCNQ.2THF]n: space group P2(1/c), monoclinic, a = 13.5501(10), b = 9.9045(10), c = 32.564(2) A, beta = 91.130(10) degrees, Z = 4. X-ray data for [[Ag(dmb)2]TCNQ.0.5TCNQo.0.5 toluene]n: space group P2(1/c), monoclinic, a = 14.3669(19), b = 9.1659(3), c = 34.012(3) A, beta = 92.140(8) degrees, Z = 4. X-ray data for [[Ag(dmb)2]TCNQ.1.5TCNQo]n: space group C2/c, monoclinic, a = 25.830(11), b = 9.680(2), c = 42.183(19) A, beta = 104.87(4) degrees, Z = 8. X-ray data for [[Ag(dmb)2]DCTC]n: space group P2(1/a), monoclinic, a = 26.273(3), b = 9.730(3), c = 31.526(3) A, beta = 112.12(2)degrees, Z = 4.     

Nickel(II) macrocyclic complexes with long alkyl pendant chain: synthesis,x-ray structure,and anion exchange property in the solid state

A nickel(II) pentaaza macrocyclic complex containing a 1-hexadecyl pendant chain, [Ni(C(25)H(55)N(5))](ClO(4))(2).H(2)O (1), was synthesized by a one-pot metal-template condensation reaction. Crystal data for 1: triclinic, Ponemacr;, a = 8.333(4) A, b = 8.356(3) A, c = 28.374(9) A, alpha = 81.865(19) degrees, beta = 86.242(18) degrees, gamma = 63.871(17) degrees, Z = 2. Solid 1 forms hydrophobic layers that are constructed by the long alkyl chains of the macrocycles. Solid 1 exchanges ClO(4)(-) with NCS(-), PF(6)(-), C(2)O(4)(2-), NO(3)(-), and CF(3)SO(3)(-) that are dissolved in water. From the reaction of [Ni(C(25)H(55)N(5))Cl(2)] with Et(3)NH(TCNQ)(2) in EtOH/DMF/acetone solution, [Ni(C(25)H(55)N(5))(TCNQ)(2)](TCNQ).(CH(3)COCH(3)) (2) (TCNQ = 7,7,8,8-tetracyano-p-quinodimethane) was prepared. Crystal data for 2: triclinic, Ponemacr;, a = 8.459(0) A, b = 13.945 (1) A, c = 26.833(2) A, alpha = 88.744(2) degrees, beta = 84.536(2) degrees, gamma = 80.089(4) degrees, Z = 2. In 2, TCNQ anions coordinate nickel(II) at the axial sites, which form pi-stacked TCNQ(-) dimers to give rise to 1-D chains. The neutral TCNQ molecules are included between the dimerized TCNQ(-) species, which construct a pi-stacked group of six TCNQ units as blocked by the long alkyl chains. Compound 2 is an electric insulator. It shows a weak signal in the EPR spectrum. The magnetic susceptibility data of 2 measured at 5-300 K exhibit a simple paramagnetism at low temperatures (<100 K) but an increase in the magnetic moment at higher temperatures due to the contribution of a thermally accessible triplet state for the antiferromagnetically coupled [TCNQ](2)(2-).     

Preparation and properties of cyclopentadienyl- and pentamethylcyclopentadienyl-titanium(IV) complexes with the C8H4S8 ligand, electrical conductivities of their oxidized species, and X-ray crystal structure of Ti(C5Me5)2(C8H4S8)

Ti(C5H5)2(C8H4S8) (1), Ti(C5Me5)2(C8H4S8) (2), [NMe4][Ti(C5H5)(C8H4S8)2] (3), and [NMe4][Ti(C5Me5)(C8H4S8)2] (4) [C8H4S8(2-) = 2-(4,5-ethylenedithio)-1,3-dithiole-2-ylidene)-1,3-dithiole-4,5- dithiolate(2-)] were prepared by reaction of Ti(C5H5)2Cl2, Ti(C5Me5)2Cl2, Ti(C5H5)Cl3, or Ti(C5Me5)Cl3 with Li2C8H4S8 or [NMe4]2[C8H4S8] in THF. They were oxidized by iodine, the ferrocenium cation, or TCNQ (7,7,8,8-tetracyano-p-quinodimethane) in CH2Cl2 or in acetone to afford one-electron-oxidized and over-one-electron-oxidized species, [Ti(C5H5)2(C8H4S8)].I3, [Ti(C5H5)2(C8H4S8)][PF6], [Ti(C5Me5)2(C8H4S8)].I3, [Ti(C5Me5)2(C8H4S8)][PF6], [Ti(C5H5)(C8H4S8)2].I0.9, [Ti(C5H5)(C8H4S8)2][TCNQ]0.3, [Ti(C5Me5)(C8H4S8)2].I2.4, and [Ti(C5Me5)(C8H4S8)2][TCNQ]0.3, with the C8H4S8 ligand-centered oxidation. They exhibited electrical conductivities of 1.6 x 10(-1) to 7.6 x 10(-4) S cm-1 measured for compacted pellets at room temperature. The crystal structure of 2 was clarified to consist of isolated dimerized units of the molecules through some sulfur-sulfur nonbonded contacts: monoclinic, P2(1)/c, a = 9.534(2) A, b = 18.227(2) A, c = 17.775(2) A, beta = 94.39(1) degrees, Z = 4.     

Delocalized TCNQ stacks in nickel and copper tetraazamacrocyclic systems

New derivatives of formula [M(dieneN4)](TCNQ)3, M = Ni or Cu and dieneN4 = cis- or trans-hexamethyltetraazacyclotetradecadiene, have been obtained. The TCNQ units show electronic delocalization and formation of 1D stacks, with no direct interactions with the metal cations. The stack is not uniform and can be seen as formed by trimeric dianions (TCNQ)3(2-). The electronic delocalization favors the conductivity in these materials, which behave as good semiconductors. The crystal structures of the trans derivatives have been solved: [Ni(transdieneN4)](TCNQ)3, triclinic, P-1, a = 8.809(2) A, b = 10.896(2) A, c = 13.727(2) A, alpha = 103.04(1) degrees, beta = 101.23(2) degrees, gamma = 109.37(2) degrees, Z = 1; [Cu(trans-dieneN4)](TCNQ)3: triclinic, P-1, a = 7.872(1) A, b = 9.840(1) A, c = 14.819(1) A, alpha = 92.32(1) degrees, beta = 95.05(1) degrees, gamma = 95.66(1) degrees, Z = 1.     

Synthesis,Crystal Structure,and Magnetic Properties of a Quasi-one-dimensional Compound Based on TCNQ

A novel compound, （IBzQI）（TCNQ）2 2 （IBzQ1=1-（4-iodobenzyl）quinolinium and TCNQ = 7,7,8,8-tetracyanoquinodimethane） has been fabricated and X-ray single-crystal structurally analyzed. This compound crystallizes in the triclinic system, space group P1 with a = 8.3540（17）, b = 13.284（3）, c = 16.185（3） А, α= 82.12（3）, β= 75.19（3）, γ= 72.34°, V = 1651.2（6） А^3, Z= 2, C_40H_21IN_9, Mr = 754.56, Dc = 1.518 g/cm^3,μ= 1.015 mm^-1, S = 1.010, F（000） = 754, R = 0.0387 and wR = 0.0948. The structure analysis shows that the anions are stacked into column with tetrads, and there are two types of TCNQ entries （TCNQ-1 and TCNQ^0） in agreement with the IR spectra analysis of the compound. The temperature dependence of the magnetic susceptibility （2-300 K） for 2 exhibits spin gap of singlet-triplet feature, and the best fit gave △/kB = 1523.4 K. In order to understand both magnetic behavior and local charge distribution of [（TCNQ）2]-unit, the molecular orbital calculations and analysis based on extended Hückel method were performed, and the results support the analyses of both crystal structure and IR spectra.     

Synthesis and molecular and electronic structures of a series of Mo3CoSe4 cluster complexes with three different metal electron populations

The synthesis, crystal structure, and magnetic properties of [Mo 3(CoCO)Se 4(dmpe) 3Cl 3] ( 1), [Mo 3(CoCl)Se 4(dmpe) 3Cl 3] ( 2), and [Mo 3(CoCl)Se 4(dmpe) 3Cl 3](TCNQ) ([ 2](TCNQ)) (dmpe = 1,2-bis(dimethylphosphanyl)ethane; TCNQ = 7,7,8,8-tetracyanoquinomethane) cubane-type complexes with 16, 15, and 14 metal electrons, respectively, are reported. These compounds complete the series of cobalt-containing Mo 3CoQ 4 (Q = S, Se) cubane-type complexes, which allows a complete analysis of the consequences of replacing the inner chalcogen and the metal electron count on the structural, magnetic, and electrochemical properties. The experimental evidence is theoretically supported and rationalized on the basis of density-functional theory calculations. For the 15-metal electron [Mo 3(CoCl)Se 4(dmpe) 3Cl 3] complex with S = (1)/ 2, both electron paramagnetic resonance and theoretical studies give support to a spin density mainly located on the heteroatom. The nature of the highest occupied molecular orbital upon chalcogen exchange within the Mo 3CoQ 4 (Q = S, Se) series remains essentially unchanged, whereas the nature of the ligand attached to Co (Cl or CO) results in a different ordering of the molecular orbital scheme. This behavior is explained by the absence of backdonation between an occupied d orbital of Co to an empty pi* Cl orbital, to yield frontier orbitals that differ from those of previous models.     

Long-range ordered magnet of a charge-transfer Ru2(4+)/TCNQ two-dimensional network compound

Two isostructural 2D assemblies composed of [Ru2(O2CCF3)4] and TCNQ or TCNQF4 in a 2:1 ratio were synthesized: [{Ru2(O2CCF3)4}2TCNQ].3(p-xylene) (1b) and [{Ru2(O2CCF3)4}2TCNQF4].3(p-xylene) (2). In 1b, the TCNQ moiety is assigned to be neutral because of no significant electron transfer from the Ru24+ units. Therefore, the magnetic property of 1b can be understood to be a paramagnetic nature of the isolated Ru24+ unit, while, a fully charge-transfer from the Ru2 units to the TCNQF4 molecules in 2 leads to charge delocalization spreading over the 2D network and allows a long-range magnetic order to occur. On the basis of an idea of the resonance scheme in charge-transfer D2A network systems, the first successful example of a charge-transferred magnet in the Ru2-TCNQ system was rationally designed by tuning redox between [Ru2]4+ and the TCNQ molecule changing from TCNQ to TCNQF4.